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By S Serp, M Duchateau, P Chevreux

Molten salt reactor (MSR) is a promising advanced reactor system aiming to the transmutation of minor actinides such as americium in order to reduce the inventory of ultimate nuclear waste. The fuel is a molten salt in which actinides are homogeneously dissolved in the liquid phase. A chloride salt may be retained for this concept, as it provides low melting point, high solubility of actinides, harder neutron spectrum. To avoid corrosion and precipitation issues, molten salt composition has to be carefully controlled with impurity content as low as possible. Obtaining pure actinide chlorides without contaminants such as oxide, oxychloride, hydroxide and water is still a challenge. To prepare actinide-bearing salt, the chlorination of actinides oxides was investigated in an unstirred reactor under flowing gas as solid-gas reaction. The carbochlorination of PuO2 were performed in the temperature range of 600 to 800°C with chlorine gas as a chlorinating agent and the presence of solid carbon. PuCl3 was successfully synthesised by this method and characterised by X-ray diffraction measurements but some impurities such as oxide phase remain inside the formed product. Refinements of anhydrous and hydrated PuCl3 phases by Le Bail method were also performed for crystalline materials definition. Conversion mainly depends on the chlorinating temperature and the contact between the oxide and the chlorinating agent. A conversion value of 70–80 per cent was achieved at 700°C from PuO2 with quite high specific surface area. The conversion rate was not improved with increasing the chlorination time. The volatilisation of Pu was observed during the carbochlorination experiments. To avoid a loss of Pu caused by sublimation, the chlorination temperature should be limited to 650°C despite that the conversion of PuO2 to PuCl3 was enhanced by increasing temperature. Both carbochlorination and hydrochlorination of AmO2 were also carried out leading to the formation of AmCl3. These first results suggest that americium oxide was chlorinated more readily than plutonium oxide. The purity of produced PuCl3 and AmCl3 still deserves further investigations.

Jun 19, 2024

The carbon-in-pulp (CIP) process is now well established in the South African gold industry, with a total of over I million metric tons of material being treated each month in six large plants. This tonnage is derived from ground ore, from filtered pulp, from calcine, and from reclaimed sand-tailings dumps. With this new process and the new large plants, those concerned with CIP are experiencing a learning process, since each new plant presents a different set of problems to be overcome. The knowledge and experience gained from these plants is being shared, and will be of benefit in the design and operation of new plants. The CIP process can be subdivided into the following unit operations: prescreening at a fine size, adsorption, acid-washing and elution, reactivation, and electrowinning. Results concerning each of these unit operations, which were obtained from pilot plants and from large-scale CIP plants in South Africa, are presented. The latest developments in each of these areas is summarized. Tables that are included as an appendix contain some information concerning the equipment in these new CIP plants plus operating results from some plants.

Jan 1, 1982

The Acid Drainage Technology Initiative (ADTI) was initiated in 1995 by federal agencies, the National Mining Association (NMA) and the Interstate Mining Compact Commission (IMCC) to identify, evaluate and develop cost-effective and practical acid drainage technologies. In 1999, ADTI was expanded through the addition of the metal mining sector, which is focused on drainage quality issues related to metal mines. ADTI addresses drainage quality issues from abandoned, active, and future coal and metal mines. The guiding principle of ADTI is to build consensus among industry, federal and state regulatory agencies on acid drainage technology development and technology transfer issues. ADTI is focusing its efforts on mine drainage prediction, sampling/monitoring, modelling and avoidance/remediation. ADTI is not a regulatory or policy development program. ADTI includes the Coal Mining Sector (CMS) and the Metal Mining Sector (MMS) under the overall guidance of the ADTI Operations Committee. The Operations Committee consists of representatives from industry, state and federal government and academia. The Coal Mining Sector includes two committees; a prediction committee and an avoidance and remediation committee. The Metal Mining Sector includes steering committee and work groups on prediction, sampling and monitoring, modelling, mitigation, and pit lakes. The Coal Mining Sector has produced two publications on the prediction and prevention of acid drainage. The Metal Mining Sector has workbooks under preparation covering the work group topics. This past winter, the Metal Mining Sector, working with the US Bureau of Land Management, presented a satellite training session on acid drainage. ADTI has evolved in response to changing needs and technologies as evidenced by the addition of the Metal Mining Sector in 1999. The Operations Committee and the members of the Coal and Metal Mining Sectors will guide future direction in response to identified issues.

Jan 1, 2003

By G J. Zhang

The shape and particle size distribution of caved ore mass in sublevel caving were investigated in this study. The paper first reviews the main factors affecting the shape and characteristic of caved ore mass in sublevel caving and then through the experimental blast testing with cement-sand concrete models, the shape and particle size distribution of caved ore mass were found out. The experimental results indicated that the shape and particle size distribution of caved ore mass was similar to that of the drawn loose body. This finding presented a new perspective for the future study on the ore drawing theory and on the optimisation of structural parameters of sublevel caving. The structural parameters must meet the principle that the shape of the drawn body is in consistency to the shape of caved ore mass.

Jul 11, 2011

The Energy Authority of NSW has wide powers and responsibilities conferred by its Act which are pertinent to the State's coal industry and its development into the next century. With respect to coal, the broad objective is to maximise the benefits to NSW and its people derived from the State's coal resources. The initial focus of the Authority's coal-related activities in the late 70's and early 80's was on petroleum substitutes from coal. Research was supported, especially on hydrogenation, and the Authority participated in the Joint Australia/Federal Republic of Germany coal-to-oil feasibility study. It also co-ordinated a State Government initiative to involve the private sector in examining the possible establishment of a synthetic fuels industry based on Hunter Valley coal. With a short-fall in world-wide petroleum supply now seen as less likely for some years, the Authority is looking also at ways of working towards the broad objective in the field of coal utilisation on both domestic and export markets. Areas of interest include possibilities for using washery rejects, means of making NSW coal more competitive as an energy source, use of coal-seam gas and new or special technologies for burning coal. The future is expected to see renewed interest in producing petroleum substitutes, and coal - as the State's major energy resource - is seen as a strong contender as a basis for such an industry. Developments in coal-based power generation are also expected to have an impact, with advanced technologies having a possible place here as well as Overseas.

Jan 1, 1987

By T Laing, M A. Abdalla, P Hagan

Open pit operators are facing a number of challenges in the area of blasting and blasting processes, such as wall control, quality of fragmentation, explosives consumption and vibration. Remaining financially viable is one of the most significant objectives for mining professionals as they work through the blasting challenges within the mining chain of processes. This objective is such a significant challenge, primarily due to the high consumption of materials and the direct consequences on the downstream processes in the mining work flow, including loading, hauling, crushing, milling and mineral concentration. This paper reviews and discusses a technique to achieve this objective, namely air-decking. The performance in a number of mines around the world is reviewed focusing on the economic contributions of air-deck blasting. Various scenarios are investigated and simulated, covering both conventional and air-deck blasting, using JKSimblast software. The scenarios explore a range of issues and found that optimum results could be achieved with a minimum amount of explosives. The results obtained from the simulations were verified with blasts at Rixs Creek Coal Mine, Australia. Based on the verification results the simulations were then modified to more accurately model the actual conditions and parameters on site and to ensure that the models derived meet the production and control requirements at the mine site. Ultimately, overall analysis and comparisons were applied to the outcomes of the conventional and air-decking blasts revealing a reduction in material consumption of around 25 per cent with consequential savings and up to a 30 per cent reduction in ground vibration.CITATION:Abdalla, M A, Laing, T and Hagan, P, 2012. The contribution of air-deck blasting to open pit mining economics, in Proceedings Eighth Open Pit OperatorsÆ Conference , pp 7-12 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 18, 2012

By D Wardiman, R Benton, D Sims, T Carr, V Singh

The Kencana underground gold mine comprises two world-class epithermal vein deposits located in the North Maluku province of Indonesia on Halmahera Island. The K1 deposit has a recent extensive mining history, whilst development of the K2 deposit is in progress. Kencana epithermal vein zones have a relatively simple planar geometry dipping 25 to 45¦ towards the East and extend 400 to 600 m along strike and down dip. True width ranges from 1 m to 20 m. Economic gold grades are generally associated with two distinct mineralisation styles: Main Zone û continuous material characterised by classic epithermal vein textures including crustiform/colloform chalky white quartz- adularia sulfide banded and brecciated veining typically grading 10 to 40 g/t Au. Bonanza Zone û semi-continuous identifiable zones within the Main Zone. Characterised by brecciated quartz-adularia sulfide banded vein æginguroÆ material typically grading 80 to 200 g/t Au. Associated with this æBonanzaÆ zone are gold grades averaging around ten times higher than the surrounding Main Zone. At the resource evaluation stage, these deposits are typically drilled on approximately 25 m by 25 m spacing. This drilling density is usually adequate to allow robust estimation of global resources, including the lateral definition of æBonanzaÆ style mineralisation. It appears intuitive at the resource definition stage to separately model the æBonanza ZoneÆ using deterministic methods such as manual interpretation and wireframing. Inevitably, however, such deterministic methods result in a simplified version of reality. Whilst the geologistÆs interpretation of the overall vein volume and lateral extent of æBonanzaÆ mineralisation has proven to be remarkably accurate, close-spaced sampling and mapping of the K1 orebody has shown that this style of mineralisation exhibits extreme short-scale geometric and spatial variability. A consequence of this short-scale geometric and grade variability is the significant uncertainty with reporting these Resources and Reserves at relatively small reporting time periods such as monthly production periods. The mining method employed at Kencana often involves extracting the full width of the mineralised vein with multiple mining passes over several months. In the past it has proven difficult to achieve accurate production budgets and forecasts at Kencana as any given mining schedule based on the resource model is acutely sensitive to the quantity and location of æBonanzaÆ material. Moreover, the degree of uncertainty or risk associated with a mining schedule significantly increases as the reporting time period becomes smaller. A further deficiency of deterministic methods for geometric modelling is the inherent lack of ability to derive confidence intervals for quantifying uncertainty and risk. The use of conditional simulation techniques can help overcome this deficiency. Geostatistical conditional simulation techniques have been applied at Kencana in an attempt to model and quantify geological and grade variability in the upcoming K2 orebody based on the experience to date with mining the K1 orebody. At Kencana, conditional simulation has provided a successful means to quantify uncertainties and risks associated with various data densities and reporting time periods. The results of this project have provided managers and planners with a clearer understanding of the likely variances and risks associated with predicting gold metal production at key reporting time periods based on data at the resource model level of resolution. With corporate requirements to adhere to mining budgets/quarterly schedules, this type of analysis allows a more scientific approach to estimating grade uncertainty in the mining schedule. Until now this has been difficult to quantify due to the extreme gold metal variability. The availability of this type of analysis allows a time-efficient rationalisation on redesigns of the mining shapes and effective communication of the likely uncertainties involved.

Jan 1, 2009

The metals titanium and zirconium and their alloys occupy individually unique positions in the catalogue of metallic materials available for engineering applications. Because of the uniqueness of their usage in the aerospace industry, in the case of titanium, and in the nuclear industry, in the case of zirconium, the except- ional resistance of both the metals to the majority of corrosive media is often overlooked. The cost factor in the application of these more exotic metals has, in the past, been a major considerat- ion in the rejection of titanium and zirconium as constructional materials in areas of usage where their superior corrosion resistance strongly favoured them over more conventional metals and alloys. The cost differential, vis-a-vis austenitic stainless steels, for example, is not a trifling matter, being of the order of 6 : 1, when compared on a weight basis. However, if one considers the cost, for, say, sheet product on an area basis, the ratio is redgced to approximately 3.4:1. If one also takes into account the enhanced performance of the more expensive material and the sub- sequent increase in service life and decrease in plant down-time, the economics of the usage of materials such as titanium becomes much more attractive and, indeed, highly competitive,

Jan 1, 1969

By J L. Merritt

The mining industry seeks to engage with and respond to stakeholders through open consultation processes during the various phases of a mining project (Department of Industry, Tourism and Resources, 2006). Two Australian Coal Association Research Program (ACARP) funded projects conducted in the Bowen Basin coalfields in Central Queensland investigated the use of a stakeholder panel for the evaluation of mine site rehabilitation. The panel members were drawn from the local and regional area, and represented neighbouring landholders, traditional owners, AgForce, local government, conservation groups and non-governmental organisations (NGOs) such as Greening Australia and the Fitzroy Basin Association. The approach of utilising stakeholders to establish rehabilitation criteria was proposed as an alternative to the established practice of assessing rehabilitated areas against a suite of quantitative completion criteria; eg >70 per cent vegetative ground cover or <5 t/ha/a soil loss. The basis of this approach recognises the reality that the definition of completion criteria has proved problematic over the last 40 years with no broad consensus reached on the suite, let alone the metrics; eg the exact cover level that will benchmark acceptance of the mine site rehabilitation.CITATION:Merritt, J L, 2016. Zooming out – learning to see rehabilitation through stakeholders’ eyes, in Proceedings Life-of-Mine 2016 Conference, pp 163–165 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

The Lihir deposit in Papua New Guinea (PNG) contains an estimated mineable reserve of 454t (14.6M oz) of gold in refractory sulphide ore. The Lihir Joint Venture has submitted a proposal to the PNG Government to develop an open pit mine and to install a process plant and associated infrastructure facilities on Lihir Island. The proposed process plant will employ whole-ore pressure oxidation technology, has a design capacity of 2.825Mt/a of ore containing 7.20 sulphide sulphur, and is expected to average 19.3t/a (620,000 oz/a) in gold production during its first 12 years of operation.An extensive program of process development testwork and feasibility engineering was completed to establish the process plant design for the Lihir Project. Summary results of this test-work as well as key design criteria, the process flowsheet, and major equipment selected for the commercial plant are presented and discussed.

Jan 1, 1994

By M Zoorabadi

Overcoring is a common technique to measure in situ rock stress using the concept of stress relief. The strains measured during overcoring are used to calculate the stress tensor assuming continuous, homogeneous, isotropic and linear elastic behaviour. This approach does not recognise any effect of the thickness of the rock annulus produced during overcoring instead assuming that the stresses are entirely a function of the difference in strain between the start of the overcoring and the end with no regard to the transient strains produced. Three-dimensional numerical modelling was used to simulate the overcoring process and investigate the impact of core diameter on the transient stresses and strains during overcoring. This study showed that in thicker core, maximum transient axial stresses and strains occur when the drill bit approaches the measuring point and greater tensile axial stresses were produced when the annulus was thinner. CITATION:Zoorabadi, M, 2018. Numerical study of annulus thickness on overcoring stress measurements, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 274–278 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By J J. Hanhiniemi, M S. Powell

A ‘Variable Blend and Rates’ model is developed for SAG mills which extends upon the JKSimMet® Variable Rates Model. Similarly, a ‘Variable Blend Residence Constrained Perfect Mixing’ Ball Mill model is also introduced, also extending upon the existing JKSimMet® model. These models are used in conjunction with JKSimMet® while employing external technical programs. The technical model is then used to inform an economic model described elsewhere in Hanhiniemi and Powell (2022), which calculate operating and unit costs based on operating conditions, design, and ore characterisation. The SAG and ball mill models include constraints beyond those in the JKSimMet® models. The SAG model constraints include Size Specific Energy (SSE) verification, charge weight limit, and assessment of the impact of media to ore composition in the charge using the SAG Charge SSE Model developed in this paper. The ball mill model includes residence time, volumetric capacity, and SSE verification constraints. These models are applied to Cortez Gold Mine in the processing of two very different ore types and their blends; ‘Horse Canyon’ which is softer in coarser sizes and competent is fine sizes, and ‘Wenban’ which is competent at coarser sizes but softer in fine sizes than Horse Canyon. Horse Canyon also has a finer run-of-mine size distribution then Wenban. The application of the model at this site included undertaking five surveys at varying blends. The behaviours of the blends and individual components is then studied in the SABC circuit. A nonlinearity is observed with throughputs increasing with blending. The newly developed modelling approach captures these responses. Controlled blending based on ore competence-by-size and size distribution was implemented by the site, which then realised significant improvements in throughput without any capital cost (Ntiamoah et al, 2020). The modelling developed in this paper is then compared to existing practice, and the new method was found to provide improved fidelity and utility. A three-dimensional surface is then developed using the model describing the SAG mill throughput capacity at varying conditions (speed-filling) versus varying blend. The change in throughput as a function of only the changing charge composition is presented. The result is nonlinear, and explanations are provided to describe this behaviour.

Aug 24, 2022

By Z Li, D Chalmers, J M. Tenney

This paper presents the findings and analysis of the investigation of effectiveness of thin spray-on liners (TSLs) as a gas management tool in underground coalmines. The project involves spraying TSL on the area surrounding gas drainage holes whereby the TSL acts as a thin membrane decreasing the permeability of the coal. This restricts air migrating through the coal seam and diluting gas from the drainage holes. There are a number of potential benefits from this technique but key points are that gas drainage holes produce gas with higher concentrations of methane. The design and execution of a field trial to investigate the effectiveness of a TSL on purity of in situ methane from gas drainage holes is presented in this report. For eight drainage holes, the results show an average increase in methane purity by 9.14 per cent and a reduction in air contamination by an average 7.93 per cent. Overall methane flow rate decreased by 27.6 L/s; however, flow rates were unreliable due to poor measuring equipment. For most holes, methane purity was not changed significantly; however, certain boreholes were responsible for most of the variation in methane purity. The boreholes showing a dramatic improvement in methane purity were likely those with intersecting cleats covered by the TSL. If the TSL was sprayed over more area, specifically in areas where the cleats are intersecting with holes, it is likely that purity of methane in the drainage holes will increase.CITATION:Tenney, J M, Chalmers, D and Li, Z, 2015. Thin spray-on liners potential in reducing dilution of in situ gas in underground coalmines, in Proceedings The Australian Mine Ventilation Conference, pp 323–328 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By D C. Ford

The Argyle AK1 orebody was discovered in 1979 and subsequently found to be a large, economically viable reserve with high grade diamondiferous ore. Production began via an open pit operation at the end of 1985 and has continued for some 25 years to present day. This, however, will come to an end in the next few years with production moving to an underground operation via block-cave mining methods.A series of studies from 2001 - 2005 was carried out; diamond drilling commenced after approval in 2006, from an exploration drive to determine the likelihood of the current proposed block cave operation.In 2006, development of the block cave project began, in order to realise the part of the orebody below the extent of the open pit mining operation.Development of the block cave technique, comprising an undercut level beneath the target zone of the orebody with subsequent extraction level 15 - 20 m beneath, relies largely on a number of block-caving parameters (hydraulic radius, rock type, structure and orientation of stress and grade of the orebody). These all have an influence on cave ability and eventual profit of the operation. Evaluation of further potential for taking this orebody beyond the block cave phase with options such as sublevel-caving are being considered for the UG-2 portion of the resource/reserve. Diamond drilling for this work is currently under revise.The challenges faced in transitioning form the surface operations to the underground, comprising a changing workforce, converging development drives, underground aquifers, major excavations and transportation of ore via automation are intriguing.

Aug 22, 2011

By S H. Sie, R Seetharam, K Naito, T Takagi

Tin-polymetallic vein type deposits are one of the major source of metal producers in the Circum Pacific Belt. This type of deposit is of great importance for the modem electronics and medical industries because of their high content of rare metals (especially indium and bismuth). We have studied two representatives, Tosham of India (Cu-In-Bi-Sn-W-Ag-Au), and Mount Pleasant of Canada (Zn-Cu-In-Bi-Sn-W), using proton and electron microprobes in order to delineate the distribution of medicallhigh-tech rare metals. The electron microprobe study showed that major indium carrier in such type of deposit are roquesite (CulnS2), sphalerite, stannite and a Cu-Zn-Fe-In-Sn-S mineral; and that indium is incorporated in sulfides by coupled substitution like Cu + In = 2(Zn + Fe). The proton microprobe showed that indium at trace levels is also present in chalcopyrite and pyrite. In addition, zinc, copper, arsenic, antimony, selenium, tin, and bismuth are common in chalcopyrite and pyrite. Arsenopyrite contains nickel, copper, zinc, silver, tin, antimony and bismuth. In chalcopyrite and pyrite, zinc, arsenic, indium, bismuth and lead are higher in Mount Pleasant ore, but silver is higher at Tosham. Also thallium and gold were found only in Tosham pyrite. The Tosham deposit is genetically related to S-type magma, while the Mount Pleasant deposit is related to A-type granite. Tosham ore contains zinc-bearing biotites that coexist with chalcopyrite in ore bodies but Mount Pleasant ore lacks such biotite. We propose that the difference in elemental abundance between the two deposits are caused by the different character of source magma and different mineral associations of the ore body.

Jan 1, 1995

By Cooke D, Large R

The Cambrian structure in the Mt Read Volcanics was produced by four deformational events: obduction of forearc-derived mafic/ultramalic complexes in the early Middle Cambrian, a middle Middle Cambrian extensional phase related to the post-collisional Mt Read volcanism and VHMS mineralisation, Middle Cambrian E-W folding, and Late Cambrian N-S folding and basin inversion. The major phase of VHMS mineralisation in western Tasmania is restricted to the very brief period of extensional tectonics within the middle Middle Cambrian. Within this period a N-S graben was produced with a complex series of transfer zones, largely striking E-W. Most VHMS mineralisation is restricted to the top of massive volcanic successions, with several mines close to Cambrian transfer structures. Many of the transfer structures continued to be active until the Devonian. The later compressional Cambrian events are not significant in localising orc formation. Within the Rosebery mine a complex pattern of minor Cambrian normal faults has a second order control on the distribution of the mineralisation.

Jan 1, 1997

Early theories of coal formation are outlined, with special emphasis on the arguments for allochthony and autochthony. Various aspects of the nature, growth, and decay of the characteristic vegetation of the brown coal peat moors, their conversion into coal, the origin of banding, and the influence of tectonics are discussed.A description of the banding in Victorian brown coals is followed by a discussion of their vitrain, fusain, and natural carbonized coal; and concludes with the nature of the coal resin and the possibilities of its extraction.The nature and derivation of inorganic matter in brown coal, based on Lessing's classification, is described. Assimilation of mineral substances in specific plants with variations due to environmental factorsare illustrated by analyses of present day trees. Consideration is then given to possible sources of salt, marcasite, and quartz in brown coal.It is shown that part of the inherent and extraneous ash may have been removed during and after coal formation. The nature and abundance of the organically combined substances in brown coal emphasizes the anomalies that may arise from estimating the total inorganic matter from ash contents.After classifying deposits on external heating surfaces of boilers, theoretical and practical aspects of slag formation, alkali matrix deposits, and the effect of sulphur and chlorine are considered.Analyses of deposits in boilers burning Victorian brown coal are tabulated.Slagging at the Yallourn power station from sand in the Yallourn open cut, and difficulties with Yallourn North Extension coal at the Maryvale paper mills are described.Tests carried out on Morwell and Yallourn coals showed that with the former, impacted deposits formed on boiler heating surfaces, and left a high percentage of chlorides on probes. Morwell briquettescompared with Yallourn briquettes also reduced the running time of a semi-industrial boiler through deposits with sodium sulphate as...

Jan 1, 1962

By D J Williams

Coal washery wastes comprise tailings, finer than 0.5 to 0.1 inn depending on the sophistication of the washery, and coarse reject, typically finer than 50 mm. Subaerial disposal of coal tailings slurry at about 30 per cent solids by mass results in the formation of a delta with an average slope of about 1 in 100, representing one extreme. The ravelling of coarse reject on loose-dumping, results in an angle of repose slope with an angle of about 37" (1 in 1.3), representing the other extreme. The pumped co-disposal of coal tailings and coarse reject results in the formation of an upper delta with an average slope of about to one in ten, between the two extremes. The depositional behaviour of these three waste streams is discussed and compared in this paper. The important depositional and material parameters, and a theoretical description of the processes involved, are also presented. Comparisons are made between the depositional behaviour of the various coal washery waste streams, and natural depositional systems, such as rivers, alluvial fans, and scree slopes.

Jan 1, 1998

The Sishen iron-ore-mine produces 3 pro= ducts with size gradings of 25 to 8 mm, 11 to 5 mm and 5 to 0,2 mm and has a product capacity of 20 Mtpa. Ore is produced at an average Fe content of 66,2 % Fe for the two coarser pro= ducts and an average of 65,3 % Fe for the fine ore product. Three stage crushing is practised to re= duce the run-of-mine ore to -90 mm after which it is screened into five different size frac= tions of which four are heavy media beneficiated in static baths and cyclones and the fifth frac= tion discarded to slimes dams. A final three stage crushing and screening process is employed to produce the final three Products which are homogenized by means of blen=ding systems nrinr to despatch.

Jan 1, 1987

By A Patwardhan, M M. Alam, K K. Thatavar

A commercial wet scrubber was used in the SIU-Joy dust control laboratory to test several concepts for improving the dust control efficiency of a wet scrubber. The concepts tested included two filter-two-spray systems, hollow and full-cone sprays, horizontal and vertical sprays, different layer filters and addition of surfactant. The optimised scrubber configuration had water-only vertical sprays for pre-wetting coarse dust, and vertical surfactant-laden water sprays for wetting ultrafine particles. This scrubber configuration reduced dust concentrations from 250 mg/m3 to 1.8 mg/m3. In comparison, the conventional scrubber configuration in the feed provides an outlet dust concentration of 3 - 4 mg/m3 in field operation. Upon successful testing and optimisation of parameters in the laboratory, field demonstration of the concepts was conducted at an Illinois coal mine. The optimised scrubber configuration was tested in the field with good results in terms of improved visibility in the face area and reduced respirable and quartz dust concentrations. Additional modifications in the field involved relocation of the scrubber suction inlets from the bottom to the side and changing the water spray configuration on the miner head. These additional changes were based on a conceptualised spatial dust distribution profile in the face area. The results of these laboratory development and field demonstration studies are presented in this paper.

Jan 1, 2005